Colour measurements were assessed using a Minolta Chroma
Metre (CR-14, Ramsey, NJ, USA) calibrated with a white plate.
Colour was expressed as CIELAB (L*a*b*) colour space, where L*
defines the lightness and a* and b* define the red-greenness and
blue-yellowness, respectively. Hue angle (H◦) was calculated as
H= arctangent b*/a*(Minolta, 2007). Leaf colour was evaluated in
the same area of the leaf for the different shoots. Colour was determined
in 9 replicates of 3 shoots